1. Session 4, Activity 2: Slides for interactive work
Facilitator notes:
Legionnaires’ disease: Risk assessment, outbreak investigation and control
Session 4, Activity 2: Slides for interactive work
Version: 2012

2. Hot and cold water systems feeding TMV’s (silvered domes on left hand side). The pipes are within a cupboard/enclosed area that could be accessed. There was localised heating of the cold water pipes as these were not insulated, as weren’t the hot water pipes.

3. Water circulation pumps
Water circulation pumps. Nothing specifically of concern – no specific defects evident.
The pipes are well insulated. During an investigation flow and return temperatures should be taken and considered.

4. A domestic hot water system (non circulating) in a home.
This photo (and others like it) have been taken in cases where the domestic water system has been linked to the case.
In the picture a hot water cylinder (lagged with foam) – will still cause localised heating to the cold water storage tank stored above.
Stagnation in the tank, accumulation of material and localised heating can result in conditions that can ensure the proliferation of legionella in the cold water system.

5. A very tricky photo/photos
A very tricky photo/photos. This is a photo of a domestic system that is part of a district heating scheme. The occupier adjusts the flow of very hot water that flows into a heat exchange system for hot water and separately for heating. The greater the flow – the more the heat exchange – the higher the cost. Several cases have occurred where flow is low and

6. Pool waters – a standard recreational pool
Pool waters – a standard recreational pool. Is Legionella usually associated with the pool water? – Not really, pool water disinfection, coagulation and filtration - and management means that there are few issues with the pool water – but rather the ‘domestic water system’ on the premises.

7. Water storage tanks should be clean and free from debris, scale and biofilms. Such tanks can provide an ideal environment for the growth of biofilms and legionella.

8. This schematic was prepared following a case that was linked to a leisure centre. This is a very poor schematic. Some schematics are good, some are excellent. They provide details as to the system – but they can be of limited use if they are not put together accurately – including all historic changes to the system and the dead legs etc.

9. Cooling tower pack – pool maintenance and in very poor condition.

10. Typical water treatment reports
Typical water treatment reports. These will be discussed in an interactive session. Opportunity to discuss the parameters that are examined as part of routine maintenance and management of the system.

11. Facilitator notes:
Acknowledgements The creation of this training material was commissioned in 2010 by ECDC to Health Protection Agency (UK) and the University of Chester (UK) with the direct involvement of Louise Brown, Janice Gidman, Emma Gilgunn-Jones, Ian Hall (on behalf of the ECDC Legionnaires Disease Outbreak Toolbox Development Group), Tim Harrison, Rob Johnston, Carol Joseph, Sandra Lai, John Lee, Falguni Naik, Nick Phin, Michelle Rivett, and Susanne Surman-Lee. The revision and update of this training material was commissioned in 2017 by ECDC to Transmissible (NL) with the direct involvement of Arnold Bosman and Kassiani Mellou.